We present parallel algorithms for the following four operations on red-black trees: construction, search, insertion, and deletion. Our parallel algorithm for constructing a red-black tree from a sorted list of n item...
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We present parallel algorithms for the following four operations on red-black trees: construction, search, insertion, and deletion. Our parallel algorithm for constructing a red-black tree from a sorted list of n items runs in O(1) time with n processors on the CRCW PRAM and runs in O(loglogn) time with n/loglogn processors on the EREW PRAM. Our construction algorithm does not require the assumptions that previous construction algorithms used. Each of our parallel algorithms for search, insertion, and deletion in red-black trees runs in O(logn + logk) time with k processors on the EREW PRAM, where k is the number of unsorted items to search for, insert, or delete and n is the number of nodes in a red-black tree. (C) 2001 Elsevier Science B.V. All rights reserved.
In this paper a parallel algorithm is given that, given a graph G = (V, E), decides whether G is a series parallel graph, and, if so, builds a decomposition tree for G of series and parallel composition rules. The alg...
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In this paper a parallel algorithm is given that, given a graph G = (V, E), decides whether G is a series parallel graph, and, if so, builds a decomposition tree for G of series and parallel composition rules. The algorithm uses O (log\E\log*\E\) time and O(\E\) operations on an EREW PRAM, and O (log \E\) time and O(\E\) operations on a CRCW PRAM. The results hold for undirected as well as for directed graphs. algorithms with the same resource bounds are described for the recognition of graphs of treewidth two, and for constructing tree decompositions of treewidth two. Hence efficient parallel algorithms can be found for a large number of graph problems on series parallel graphs and graphs with treewidth two. These include many well-known problems like all problems that can be stated in monadic second-order logic.
We present a new BSP/CGM parallel algorithm for the Transitive Closure Problem. Our algorithm uses O(n(3)/palpha) local computation time with O(p/alpha) communication rounds, where a is the size in bits that can be st...
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ISBN:
(纸本)0769522408
We present a new BSP/CGM parallel algorithm for the Transitive Closure Problem. Our algorithm uses O(n(3)/palpha) local computation time with O(p/alpha) communication rounds, where a is the size in bits that can be stored in a primitive data item. For all the randomly generated graphs that were used in the tests, the number of communication rounds was bounded by log p/alpha + 1. Our algorithm, even for the worst case, improves the previous results. The algorithm was implemented and the results show the efficiency and scalability of the presented algorithm and compare favorably with other parallel implementations.
In this paper a novel concurrent PSO(CONPSO) algorithm is proposed to alleviate the premature convergence problem of PSO algorithm. It is a type of parallel algorithm in which modified PSO and FDR-PSO algorithms are s...
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ISBN:
(纸本)0780385152
In this paper a novel concurrent PSO(CONPSO) algorithm is proposed to alleviate the premature convergence problem of PSO algorithm. It is a type of parallel algorithm in which modified PSO and FDR-PSO algorithms are simulated concurrently with frequent message passing between them. This algorithm avoids the possible crosstalk effect of pbest and gbest terms with nbest term in FDR-PSO. Thereby search efficiency of proposed algorithm is improved. In order to demonstrate the effectiveness of the proposed algorithm experiments were conducted on six benchmark continuous optimization problems. Results clearly demonstrate the superior performance of the proposed algorithm in terms of solution quality, average computation time and consistency. This algorithm is very much suitable for the implementation in parallel computer.
In this paper we present a significant extension of the quantified equation based algorithm class of piecewise regular algorithms. The main contributions of the following paper are: (1) the class of piecewise regular ...
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ISBN:
(纸本)0769522262
In this paper we present a significant extension of the quantified equation based algorithm class of piecewise regular algorithms. The main contributions of the following paper are: (1) the class of piecewise regular algorithms is extended by allowing run-time dependent conditionals, (2) a mixed integer linear program is given to derive optimal schedules of the novel class we call dynamic piecewise regular algorithms, and (3) in order to achieve highest performance, we present a speculative scheduling approach. The results are applied to an illustrative example.
We propose a new block algorithm for the generalized Sylvester-observer equation : XA - FXE = GC, where the matrices A, E, and C are given, the matrices X, F, and G need to be computed, and matrix E could be singular....
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ISBN:
(纸本)0780386825
We propose a new block algorithm for the generalized Sylvester-observer equation : XA - FXE = GC, where the matrices A, E, and C are given, the matrices X, F, and G need to be computed, and matrix E could be singular. The algorithm is based on an orthogonal decomposition of the triplet (A, E, C) to observer-Hessenberg-triangular form. It is a natural generalization of the widely-known observer-Hessenberg algorithm for the Sylvester-observer equation : XA - FX = GC, which arises in state estimation of a standard first-order state-space control system. An application of the proposed algorithm is made to state estimation of second-order control systems modeling a wide variety of vibrating structures. For dense un-structured data, the algorithm is more efficient than the recently proposed SVD-based algorithm of the authors, numerically reliable and heavily composed of Basic Linear Algebra Subprograms -Level 3 (BLAS 3) operations, which make it an ideal candidate for high-performance computing.
Turbo equalization scheme provides nearly optimal performance but when it is employed in sparse multipath channel environments, the equalizer complexity can prohibit its use. In this paper, we develop a parallel trell...
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ISBN:
(纸本)0780383443
Turbo equalization scheme provides nearly optimal performance but when it is employed in sparse multipath channel environments, the equalizer complexity can prohibit its use. In this paper, we develop a parallel trellis n-tap maximum a posteriori (MAP) equalizer which can consider n dominant taps of sparse channels in the trellis with reasonable complexity It is shown that turbo equalizations employing n-tap MAP equalizer can achieve nearly the same asymptotic performance of optimal maximum likelihood (ML) detector assuming perfect intersymbol interference (ISI) Cancellation which is required for n-tap MAP We also propose a tap allocation scheme for time-varying minimum mean squared error (MMSE) equalizer which can significantly reduce complexity and provide good tracking performance in time-varying channels.
The capabilities of reliable computations in one-dimensional cellular automata are investigated by means of the Early Bird Problem. The problem is typical for situations in massively parallel systems where a global be...
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The capabilities of reliable computations in one-dimensional cellular automata are investigated by means of the Early Bird Problem. The problem is typical for situations in massively parallel systems where a global behavior must be achieved by only local interactions between the single elements. The cells that cause the misoperations are assumed to behave as follows. They run a self-diagnosis before the actual computation once. The result is stored locally such that the working state of a cell becomes visible to its neighbors. A non-working (defective) cell cannot modify information but is able to transmit it unchanged with unit speed. We present an O(n log(n) log(n))-time fault-tolerant solution of the Early Bird Problem.
This paper presents a complete and optimal framework for extending basic graph planning to operate in partitioned problem spaces. These spaces typically occur in systems that implement a hierarchy or contain data of v...
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This paper presents a complete and optimal framework for extending basic graph planning to operate in partitioned problem spaces. These spaces typically occur in systems that implement a hierarchy or contain data of various resolutions. An algorithm for the framework will be presented along with a proof of optimality. Finally, an example implementation for mobile robot path planning will be discussed.
A new parallel normalized explicit preconditioned conjugate gradient method in conjunction with normalized approximate inverse matrix techniques is presented for solving efficiently sparse linear systems on multi-comp...
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A new parallel normalized explicit preconditioned conjugate gradient method in conjunction with normalized approximate inverse matrix techniques is presented for solving efficiently sparse linear systems on multi-computer systems. Application of the proposed method on a three dimensional boundary value problem is discussed and numerical results are given. The implementation and performance on a distributed, memory MIMD machine, using message passing interface (MPI) is also investigated.
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